We currently tightly couple dcache clean with icache invalidation, but KVM could do without the initial flush to PoU, as we've already flushed things to PoC. Let's introduce invalidate_icache_range which is limited to invalidating the icache from the linear mapping (and thus has none of the userspace fault handling complexity), and wire it in KVM instead of flush_icache_range. Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> --- arch/arm64/include/asm/cacheflush.h | 8 ++++++++ arch/arm64/include/asm/kvm_mmu.h | 4 ++-- arch/arm64/mm/cache.S | 24 ++++++++++++++++++++++++ 3 files changed, 34 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h index 76d1cc85d5b1..ad56406944c6 100644 --- a/arch/arm64/include/asm/cacheflush.h +++ b/arch/arm64/include/asm/cacheflush.h @@ -52,6 +52,13 @@ * - start - virtual start address * - end - virtual end address * + * invalidate_icache_range(start, end) + * + * Invalidate the I-cache in the region described by start, end. + * Linear mapping only! + * - start - virtual start address + * - end - virtual end address + * * __flush_cache_user_range(start, end) * * Ensure coherency between the I-cache and the D-cache in the @@ -66,6 +73,7 @@ * - size - region size */ extern void flush_icache_range(unsigned long start, unsigned long end); +extern void invalidate_icache_range(unsigned long start, unsigned long end); extern void __flush_dcache_area(void *addr, size_t len); extern void __inval_dcache_area(void *addr, size_t len); extern void __clean_dcache_area_poc(void *addr, size_t len); diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 4c4cb4f0e34f..48d31ca2ce9c 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -250,8 +250,8 @@ static inline void __coherent_icache_guest_page(struct kvm_vcpu *vcpu, /* PIPT or VPIPT at EL2 (see comment in __kvm_tlb_flush_vmid_ipa) */ void *va = page_address(pfn_to_page(pfn)); - flush_icache_range((unsigned long)va, - (unsigned long)va + size); + invalidate_icache_range((unsigned long)va, + (unsigned long)va + size); } } diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S index 7f1dbe962cf5..0c330666a8c9 100644 --- a/arch/arm64/mm/cache.S +++ b/arch/arm64/mm/cache.S @@ -80,6 +80,30 @@ USER(9f, ic ivau, x4 ) // invalidate I line PoU ENDPROC(flush_icache_range) ENDPROC(__flush_cache_user_range) +/* + * invalidate_icache_range(start,end) + * + * Ensure that the I cache is invalid within specified region. This + * assumes that this is done on the linear mapping. Do not use it + * on a userspace range, as this may fault horribly. + * + * - start - virtual start address of region + * - end - virtual end address of region + */ +ENTRY(invalidate_icache_range) + icache_line_size x2, x3 + sub x3, x2, #1 + bic x4, x0, x3 +1: + ic ivau, x4 // invalidate I line PoU + add x4, x4, x2 + cmp x4, x1 + b.lo 1b + dsb ish + isb + ret +ENDPROC(invalidate_icache_range) + /* * __flush_dcache_area(kaddr, size) * -- 2.14.1 _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
